Transformation of Erosion Types on Loess Slope by REE Tracking

REE Tracking was adopted to study the transformation of erosion types on loess slope and the results indicated that the slope runoffs was correlated with the erosion ratios at the coefficients ranging within 0.84～0.94 and this indicated the variation tendency of erosion ratios basically agreed with the runoffs; the major erosion type is sheet erosion during the initial slope runoff generation and the sheet erosions separately accounted for 71%, 48% and 49% of the total; as rainfalls went on, the rill erosions continuously increased, indicating gradual transformation from sheet erosion into rill erosion. The examination of the origins of erosion silts revealed the relative erosion was always below 10% in the upper slope section; comparison of the relative rill erosions in different slope sections showed that rill erosions mainly originated in the section spanning from 0 to 4 m away from slope foot.